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Description:
A large body of research has depicted relative arousal of the left and right cerebral hemispheres as related to utilization of particular defensive coping styles, level of anxiety, and perceptual styles. The right and left hemispheres are also presented in the literature as differing in visual-spatial and verbal-auditory short term memory abilities. The present research studied 127 right handed undergraduates' relative performance on forward spatial and digits memory spans in relation to hemispheric lateralization and other perceptual and personality variables hypothesized in the literature to be related to hemispheric arousal. It was hypothesized that the forward spatial and digit memory spans would display asymmetrical sensitivity to hemispheric arousal. That is, in a series of successive factor analyses, a hemispheric balance factor, a trait anxiety factor, and a short term memory factor would emerge. The three factors were hypothesized to be unrelated to each other. During an initial group pretesting, subjects were given pencil and paper measures of handedness, trait anxiety, and several defensive coping styles. During a second individual testing, subjects were administered measures of short term memory, field independence, and a computerized presentation of geometric designs which measured the subjects ability to detect differences which occurred at either the global or analytic level (Navon task). The factor analyses revealed only the hypothesized trait anxiety factor. The hypothesized short term memory and hemispheric balance of arousal factors did not emerge. Instead, a. defensive coping style factor and separate verbal—auditory and visual-spatial short term memory factors emerged. Several methodological difficulties of the present study which possibly contributed to the failure of the two hypothesized factors to emerge were discussed. Several additional findings, including sex differences in hemispheric lateralization, were presented. Also, signal detection analysis revealed a pattern such that trait anxious subjects were biased toward over-reporting differences on the Navon task. ...

Description:
The nucleus circularis has been linked to a role in regulating osmotic thirst but evidence has also shown that full bilateral destruction of the nucleus circularis was not necessary to achieve a deficit in drinking behavior after an osmotic challenge. The present study attempted to answer two primary research questions. The first question was whether osmoreceptive cells existed around the nucleus circularis in a homogeneous fashion or if these cells existed in a structured fashion stretching from the nucleus circularis forward. The second question was whether animals with lesions of the nucleus circularis and the surrounding areas were different in normal daily water intake than animals with no lesions. The first question was approached by lesioning the nucleus circularis, the area one millimeter anterior to the nucleus circularis, one millimeter posterior to the nucleus circularis, one half of a millimeter medial to the nucleus circularis and using a sham group which had the electrode passed through the brain to a spot one millimeter above the nucleus circularis but passing no current. All animals were then given an osmotic challenge which consisted of half of each group with an injection of hypertonic saline while the other half of each group was given isotonic saline. After a five-day recovery period, the injection procedure was reversed. Water consumption on each test day was measured at ten-minute intervals for one hour. Difference scores were then computed by subtracting the amount of water consumed after hypertonic saline injection from the amount of water consumed after isotonic saline injection. The difference scores were then used in an analysis of variance which revealed a significant difference between groups. A subsequent post hoc test showed that the nucleus circularis group was different from all other groups except for the anterior lesion group which showed a trend in the ...

Description:
The study reviews the structural and psychometric underpinnings of Loevinger's theory of ego development. It is noted that the current literature investigating the validity of Loevinger's model has not adequately addressed the structural assumptions of the theory. "Process" variables are hypothesized to vary depending on the process of structural change. Two such variables, cognitive complexity and the organization of cognitive constructs, were measured in 73 college students, staff, and faculty members in three North Texas institutions. Level of ego development, measured by the Washington University Sentence Completion Test, was assessed in each subject and the pattern of cognitive complexity and construct organization was evaluated across ego levels. Results offer only limited support for the stage model's structural assumptions. Discussion highlights several inadequacies in Loevinger's instrument and offers a direction for possible revision. Implications of the results are examined in terms of current theoretical issues.